Cardiovascular disease, also sometimes referred to as heart disease, cardiac disease or cardiopathy, is an umbrella term for a variety of diseases affecting the heart. Cardiovascular disease includes any of a number of specific diseases that affect the heart itself and/or the blood vessel system, especially the veins and arteries leading to and from the heart. Cardiovascular disease represents one of the more prevalent diseases affecting middle-aged and older-aged individuals in both Western and Eastern societies. As of 2007, cardiovascular disease was the leading cause of death in the United States, England, Canada and Wales, accounting for 25.4% of the total deaths in the United States.
In the United States, the most common type of cardiovascular disease is coronary artery disease (CAD). Coronary artery disease is a disease of the artery caused by the accumulation of atheromatous plaques within the walls of the arteries that supply the myocardium (the heart muscle). Angina pectoris (chest pain) and myocardial infarction (heart attack) are symptoms of and conditions caused by coronary artery disease.
Another type of cardiovascular disease is ischemic heart disease. Ischemia is defined as the inadequate flow of blood to a part of the body caused by constriction or blockage of the blood vessels supplying it. Ischemia of the heart muscle produces angina pectoris. Angina pectoris may be classified as either stable angina pectoris or unstable angina pectoris. Stable angina pectoris is angina pectoris induced by exercise and relieved by rest. Stable angina pectoris occurs when the demand for blood by the heart exceeds the supply of the blood provided by the coronary arteries.
Unstable angina pectoris, also known as “crescendo angina,” is a form of acute coronary syndrome. It is defined as angina pectoris that changes or worsens. It occurs unpredictably at rest and may be a serious indicator of an impending heart attack. What differentiates stable angina from unstable angina (other than symptoms) is the pathophysiology of the atherosclerosis. The pathophysiology of unstable angina is the reduction of coronary flow due to transient platelet aggregation. In stable angina, the developing atheroma is protected with a fibrous cap. This cap (atherosclerotic plaque) may rupture in unstable angina, allowing blood clots to precipitate and further decrease the lumen of the coronary vessel. This explains why an unstable angina appears to be independent of activity.
There are currently a wide variety of methods that can be used to treat patients with cardiovascular diseases. These include risk factor reduction (e.g., diet, exercise, stress reduction), pharmacologic therapy (drugs), and invasive and interventional therapies as practiced by cardiologists and surgeons (e.g., bypass surgery).
Despite all the therapeutic measures available and practiced today, many patients remain severely incapacitated by their cardiovascular disease. Thus, in recent years there has been both a profound interest and acceptance of a number of alternative therapies. These therapies have emerged because none of the more usual therapies have been completely effective in eliminating either the symptoms or the adverse outcomes resulting from these diseases. Further, many mainstay therapies are associated with side effects that surprising numbers of patients find unacceptable. Therefore, there has been a surge of interest in alternative therapies. See, e.g., J. C. Longhurst “Central and Peripheral Neural Mechanisms of Acupuncture in Myocardial Ischemia”, International Congress Series 1238 (2002) 79-87 (hereafter “Longhurst (2002)”); C. Mannheimer et al., “The Problem of Chronic Refractory Angina,” European Heart Journal (2002) 23, 355-370 (hereafter “Mannheimer (2002)”); J. E. Sanderson, “Electrical Neurostimulators for Pain Relief in Angina,” British Heart Journal (1990) 63:141-143 (hereafter “Sanderson (1990)”).
The alternative approaches that have emerged in the medical management of cardiovascular disease include neuromodulation techniques; e.g., transcutaneous electric nerve stimulation (TENS) and spinal cord stimulation (SCS). Mannheimer (2002) at 360-362.
Neuromodulation techniques, including both TENS and SCS, appear to be safe and generally effective methods of treating angina pectoris. Transcutaneous electric nerve stimulation (TENS) is a neuromodulation technique that is comparable to needle acupuncture. However, instead of needles, standard electrodes are applied over the painful area of the chest wall. The device can usually be used by the patient at home after instruction. When an angina attack occurs or is anticipated, the patient applies stimulation for one to three minutes. It is essential to place the electrodes so that the stimulation paresthesia cover the area of angina pain, as this is the only way to ensure that the proper spinal segment is activated; i.e., the segment that supplies the heart with nerves. Id at 361.
Disadvantageously, skin irritation develops in a large number of patients, making it difficult to continue with this form of TENS therapy. Thus, if long term neuromodulation treatment is needed, as in angina, spinal cord stimulation (SCS) is typically used as a preferable treatment modality. Clinical observations also suggest that spinal cord stimulation may be more effective than TENS. Thus, TENS has recently been used more as a test method for planned implantation, to determine whether myocardial ischemia is really the cause of the patient's pain and to evaluate whether the patient shows good enough compliance to handle a spinal cord stimulator. Id.
Spinal cord stimulation requires implantation surgery. Implantation of the spinal cord system is performed under local anesthesia. The electrode is positioned epidurally so that paresthesia is produced in the region of angina pain radiation. The patient carries an implantable pulse generator in a subcutaneous pouch, typically below the left costal arch (rib cage). The electrode is then connected to the pulse generator by tunneling a subcutaneous lead from the epidural space (adjacent the spine on the back side of the patient) to the subcutaneous pouch below the patient's rib cage (on the front side of the patient). The system is similar to a pacemaker with the electrode placed in the epidural space instead of the heart. Id.
The TENS and SCS methods described above are potent and are capable of, at least temporarily (in the case of TENS), treating myocardial ischemia, such as angina pectoris. However, the use of TENS provides only temporary relief, and use of an SCS system is highly invasive and has potentially debilitating side effects. To use an SCS device to treat angina pectoris requires that a lead must be tunneled all the way from the back side of the patient to the front side of the patient. Such a method is as invasive as, and suffers from most of the same problems as, any major surgery. In addition, the complications associated with tunneling and removal of leads, which include infection, breakage, as well as the need to perform additional surgery, are not trivial.
Another alternative approach for treating cardiovascular disease, and a host of other physiological conditions, illnesses and deficiencies, is acupuncture, which includes traditional acupuncture, acupressure. Acupuncture has been practiced in Eastern civilizations (principally China, but also other Asian countries) for at least 2500 years. It is still practiced today throughout many parts of the world, including the United States and Europe. A good summary of the history of acupuncture, and its potential applications may be found in Cheung, et al., “The Mechanism of Acupuncture Therapy and Clinical Case Studies”, (Taylor & Francis, publisher) (2001) ISBN 0-415-27254-8, hereafter referred to as “Cheung, Mechanism of Acupuncture, 2001.” The Forward, as well as Chapters 1-3, 5, 7, 8, 12 and 13 of Cheung, Mechanism of Acupuncture, 2001, are incorporated herein by reference.
Despite the practice in Eastern countries for over 2500 years, it was not until President Richard Nixon visited China (in 1972) that acupuncture began to be accepted in Western countries, such as the United States and Europe. One of the reporters who accompanied Nixon during his visit to China, James Reston, from the New York Times, received acupuncture in China for post-operative pain after undergoing an emergency appendectomy under standard anesthesia. Reston experienced pain relief from the acupuncture and wrote about it in The New York Times. In 1973 the American Internal Revenue Service allowed acupuncture to be deducted as a medical expense. Following Nixon's visit to China, and as immigrants began flowing from China to Western countries, the demand for acupuncture increased steadily. Today, acupuncture therapy is viewed by many as a viable alternative form of medical treatment, alongside Western therapies. Moreover, acupuncture treatment is now covered, at least in part, by most insurance carriers. Further, payment for acupuncture services consumes a not insignificant portion of healthcare expenditures in the U.S. and Europe. See, generally, Cheung, Mechanism of Acupuncture, 2001, vii.
Acupuncture is an alternative medicine that treats patients by insertion and manipulation of needles in the body at selected points. Novak, Patricia D. et al (1995). Dorland's Pocket Medical Dictionary (25th ed.), Philadelphia: (W. B. Saunders Publisher), ISBN 0-7216-5738-9. The locations where the acupuncture needles are inserted are referred to herein as “acupuncture points” or simply just “acupoints”. The location of acupoints in the human body has been developed over thousands of years of acupuncture practice, and maps showing the location of acupoints in the human body are readily available in acupuncture books or online. Acupoints are typically identified by various letter/number combinations, e.g., L6, S37. The maps that show the location of the acupoints may also identify what condition, illness or deficiency the particular acupoint affects when manipulation of needles inserted at the acupoint is undertaken.
References to the acupoints in the literature are not always consistent with respect to the format of the letter/number combination. Some acupoints are identified by a name only, e.g., Tongi. The same acupoint may be identified by others by the name followed with a letter/number combination placed in parenthesis, e.g., Tongi (HT5). Alternatively, the acupoint may be identified by its letter/number combination followed by its name, e.g., HT5 (Tongi). The first letter typically refers to a body organ, or other tissue location associated with, or affected by, that acupoint. However, usually only the letter is used in referring to the acupoint, but not always. Thus, for example, the acupoint P-6 is the same as acupoint Pericardium 6 which is the same as PC-6 which is the same as Pe 6 which is the same as Neiguan. For purposes of this patent application, unless specifically stated otherwise, all references to acupoints that use the same name, or the same first letter and the same number, and regardless of slight differences in second letters and formatting, are intended to refer to the same acupoint. Thus, for example, the acupoint Neiguan is the same acupoint as Neiguan (P6), which is the same acupoint as Neiguan (PC6), which is the same acupoint as PC6 (Neiguan), which is the same acupoint as Neiguan (PC-6), which is the same acupoint as Neiguan (Pe-6), which is the same acupoint as P6, P 6, PC6 or PC-6 or Pe 6.
An excellent reference book that identifies all of the traditional acupoints within the human body is WHO STANDARD ACUPUNCTURE POINT LOCATIONS IN THE WESTERN PACIFIC REGION, published by the World Health Organization (WHO), Western Pacific Region, 2008 (updated and reprinted 2009), ISBN 978 92 9061 248 7 (hereafter “WHO Standard Acupuncture Point Locations 2008”). The Table of Contents, Forward (page v-vi) and General Guidelines for Acupuncture Point Locations (pages 1-21), as well as pages 151 and 154 (which pages illustrate with particularity the location of acupoint PC6) of the WHO Standard Acupuncture Point Locations 2008 are referred to herein as Appendix D.
While many in the scientific and medical community are highly critical of the historical roots upon which acupuncture has developed, (e.g., claiming that the existence of meridians, qi, yin and yang, and the like have no scientific basis), see, e.g., http://en.wikipedia.org/wiki/Acupuncture, few can refute the vast amount of successful clinical and other data, accumulated over centuries of acupuncture practice, that shows needle manipulation applied at certain acupoints is quite effective.
The World Health Organization and the United States' National Institutes of Health (NIH) have stated that acupuncture can be effective in the treatment of neurological conditions and pain. Reports from the USA's National Center for Complementary and Alternative Medicine (NCCAM), the American Medical Association (AMA) and various USA government reports have studied and commented on the efficacy of acupuncture. There is general agreement that acupuncture is safe when administered by well-trained practitioners using sterile needles, but not on its efficacy as a medical procedure.
An early critic of acupuncture, Felix Mann, who was the author of the first comprehensive English language acupuncture textbook Acupuncture: The Ancient Chinese Art of Healing, stated that “The traditional acupuncture points are no more real than the black spots a drunkard sees in front of his eyes.” Mann compared the meridians to the meridians of longitude used in geography—an imaginary human construct. Mann, Felix (2000). Reinventing acupuncture: a new concept of ancient medicine. Oxford: Butterworth-Heinemann. pp. 14; 31. ISBN 0-7506-4857-0. Mann attempted to combine his medical knowledge with that of Chinese theory. In spite of his protestations about the theory, however, he apparently believed there must be something to it, because he was fascinated by it and trained many people in the West with the parts of it he borrowed. He also wrote many books on this subject. His legacy is that there is now a college in London and a system of needling that is known as “Medical Acupuncture”. Today this college trains doctors and Western medical professionals only.
For purposes of this patent application, the arguments for and against acupuncture are interesting, but not that relevant. What is important is that a body of literature exists that identifies several acupoints within the human body that, rightly or wrongly, have been identified as having an influence on, or are otherwise somehow related to, the treatment of various physiological conditions, deficiencies or illnesses, including pain and other conditions associated with myocardial ischemia, such as angina pectoris. With respect to these acupoints, the facts speak for themselves. Either these points do or do not affect the conditions, deficiencies or illnesses with which they have been linked. The problem lies in trying to ascertain what is fact from what is fiction. This problem is made more difficult when conducting research on this topic because the insertion of needles, and the manipulation of the needles once inserted, is more of an art than a science, and results from such research become highly subjective. What is needed is a much more regimented approach for doing acupuncture research.
It should also be noted that other medical research, not associated with acupuncture research, has over the years identified nerves and other locations throughout a patient's body where the application of electrical stimulation produces a beneficial effect for the patient. Indeed, the entire field of neurostimulation deals with identifying locations in the body where electrical stimulation can be applied in order to provide a therapeutic effect for a patient. For purposes of this patent application, such known locations within the body are treated essentially the same as acupoints—they provide a “target” location where electrical stimulation may be applied to achieve a beneficial result, whether that beneficial result is to reduce pain, to treat myocardial ischemia, to treat hypertension, to mitigate some other form of cardiovascular disease or to address some other issue associated with a disease or condition of the patient.
Returning to the discussion regarding acupuncture, some have proposed applying moderate electrical stimulation at selected acupuncture points through needles that have been inserted at those points. Such electrical stimulation is known as electroacupuncture (EA). According to Acupuncture Today, a trade journal for acupuncturists: “Electroacupuncture is quite similar to traditional acupuncture in that the same points are stimulated during treatment. As with traditional acupuncture, needles are inserted on specific points along the body. The needles are then attached to a device that generates continuous electric pulses using small clips. These devices are used to adjust the frequency and intensity of the impulse being delivered, depending on the condition being treated. Electroacupuncture uses two needles at a time so that the impulses can pass from one needle to the other. Several pairs of needles can be stimulated simultaneously, usually for no more than 30 minutes at a time.” “Acupuncture Today: Electroacupuncture”. 2004 2 Jan.
Recent research has reported the use of electroacupuncture (EA) for the treatment of myocardial ischemia and pain relief in angina. See, e.g., J. Gao, et al., “Acupuncture pretreatment protects heart from injury in rats with myocardial ischemia and reperfusion via inhibition of the 1-adrenoceptor signaling pathway,” Life Sciences 80 (2007) 1484-1489 (hereafter “Gao (2007)”); Longhurst (2002); P. Li et al., “Reversal of Reflex-Induced Myocardial Ischemia by Median Nerve Stimulation: A Feline Model of Electroacupuncture,” American Heart Association Circulation 1998, 97:1186-1194 (hereafter “Li (1998)”); Sanderson (1990).
The reason why acupuncture, including EA, can be used to treat angina is discussed at length in Cheung, Mechanism of Acupuncture, 2001, chapter 8, previously incorporated herein by reference.
Similar techniques for using electrical devices, including external EA devices, for stimulating peripheral nerves and other body locations for treatment of various maladies are known in the art. See, e.g., U.S. Pat. Nos. 4,535,784; 4,566,064; 5,195,517; 5,250,068; 5,251,637; 5,891,181; 6,393,324; 6,006,134; 7,171,266; and 7,171,266. The methods and devices disclosed in these patents, however, typically utilize either large implantable stimulators having long leads that must be tunneled through tissue to reach the desired stimulation site, or use external devices that must interface with implanted electrodes via percutaneous leads or wires passing through the skin. Such devices and methods are still far too invasive, or are ineffective, and thus are subject to the same limitations and concerns, as are the previously described electrical stimulation devices.
From the above, it is seen that there is a need in the art for a less invasive device and technique for electroacupuncture stimulation of acupoints that does not require the continual use of needles inserted through the skin, or long insulated wires implanted or inserted into blood vessels, for the purposes of treating cardiovascular diseases.